1. Field of the Invention
The present invention relates to a user interface for a portable electronic device. More particularly, the present invention provides a user interface with flexible display panel capabilities and flexible touch sensor capabilities for portable electronic devices.
2. Related Art
Advances in computer technology have enabled the further miniaturization of the components required to build computer systems. As such, new categories of computer systems have been created. One of the newer categories of computer systems is the portable, hand held, or “palmtop” computer system, also referred to as a personal digital assistant or PDA. Other examples of a portable computer system include electronic address books, electronic day planners, electronic schedulers and the like.
A palmtop computer system is a computer that is small enough to be held in the user's hand and as such is “palm-sized.” As a result, palmtops are readily carried about in the user's briefcase, purse, and in some instances, in the user's pocket. By virtue of its size, the palmtop computer, being inherently lightweight, is therefore exceptionally portable and convenient.
The continuing miniaturization of computer systems enables a user to now carry in their pocket the equivalent of a computer system that once occupied an entire room. The miniaturization has also reduced the functionality of the palmtop computer system. To support the diminutive form factor of the palmtop computer, certain functions and components normally associated with full sized computers have been reduced or eliminated.
One of the components whose functionality has been reduced is the display panel. To comply with the form factor of the portable computer, smaller graphic panels with reduced graphic resolution have been developed. By virtue of reducing both the size of the display panel and the resolution thereof, less information is now visible to the user.
Additionally, another drawback to the portable computer is the display panel itself. While utilization of the liquid crystal display (LCD) has, in part, enabled the further development of the portable computer system, it is not without some limitations. An LCD is constructed using glass, and as such, is thick, rigid, and relatively heavy for its size. Additionally, liquid crystal displays are usually visible from one position, and as such, the information displayed is often difficult to see. Another drawback is that some LCDs require backlighting for illumination of the display area which is a constant draw on the retained power within a portable computer.
The keyboard, another component that is normally associated with a full sized computer, has, in this instance, been completely eliminated from the form factor of the portable computer. By eliminating the keyboard or alphanumeric input device, an alternative means or device that would enable a user to enter and/or manipulate data had to be developed. One such device that was developed to overcome the elimination of the keyboard, while still conforming to the form factor of the portable computer, is the touchable panel, or touch screen. In essence, the touch panel enables registration and interpretation of contact between the panel and the tip of a stylus utilized by a user. As shown in FIG. 1 (Prior Art), the touch panel is disposed on the top surface area of the LCD, such that it is accessible to the user.
FIG. 1 (Prior Art) is an cross-sectioned illustrated view of exemplary touch panel/LCD device 9. Frame structures 11L and 11R as well as supporting shelves 12L and 12R and 13L and 13R are disposed, respectively, along the left and right sides of touch panel/LCD 9. Supporting shelves 12L and 12R are designed to provide edge support for top film component 14. Supporting shelves 13L and 13R are designed to provide edge support for substrate component 16.
FIG. 1 (Prior Art) further depicts, from top to bottom, the various components that comprise touch panel/LCD 9, which is a combination of touch screen 10 and LCD 20. Touch screen 10 is comprised of layers 14, 15, and 16. Commencing at the top and moving downward, top film layer 14 is shown. Top film layer 14 is the surface of touch panel/LCD 9 that is contacted by the user's stylus. Spacer layer 15 is shown as disposed below top film layer 14. Substrate layer 16 is shown as disposed beneath spacer layer 15. LCD 20, shown as disposed beneath substrate layer 16 is comprised of layers 17, 18, and 19. Thermotropic liquid crystal layer 18 is shown as sandwiched between upper glass layer 17 and lower glass layer 19. Backlighter 21, shown as disposed at the bottom of touch panel/LCD 9, provides the illumination thereof. In another exemplary example, backlighter 21 may be repositioned below substrate 16 and above upper glass layer 17, and, accordingly, is termed frontlighting, due to its orientation relative to LCD 20.
It should be appreciated that in the exemplary touch panel/LCD device, as depicted in FIG. 1 (Prior Art), inherent drawbacks are present. One drawback is the overall height of touch panel/LCD 9, which is approximately four millimeters, making it relatively thick for a portable computer system.
Another drawback is that, because of the amount of space between the touch surface of the touch screen and LCD, there is what is commonly referred to as the parallax effect. Simply stated, the parallax effect is a type of visual spatial distortion such that the actual point of contact on the touch screen does not correspond to the intended target area of the LCD. This is analogous to a stick being immersed in water, such that the stick takes on a bent or distorted appearance.
An additional drawback is that the amount of light that comes from the LCD through the touch screen to be viewed by the user is only about 80% of the available light. In a reflective display, that amount is further reduced to about 64%. This reduces the overall contrast, clarity, and quality of the display as seen by the user.